In industrial facilities such as food or beverage plants, it is often necessary to convert a mass of articles into two or more single files of articles. For example, single filing may be used to distribute the articles to a plurality of relatively slow downstream stations in order to improve or maintain article throughput in the plant, or to arrange articles abreast in transverse rows for packing or other downstream operations.
In order to improve the usefulness of laning conveyors, prior designs provide mechanisms for lane width adjustment. U.S. Pat. Nos. 4,880,104 and 4,986,056 disclose a lane adjusting apparatus including movable lane guides connected by threaded telescoping elements to a common drive shaft for uniform width adjustment. U.S. Pat. No. 2,951,574 discloses opposite thread mounted outer lanes uniformly movable together and apart upon rotation of the shaft as intermediate lanes are coordinately slid along the shaft with "lazy-tongs linkages." U.S. Pat. No. 3,767,027 discloses pantographs and bushings for moving lanes to maintain uniform widths. U.S. Pat. No. 3,554,353 discloses opposite thread mounted outside lane guides and coil springs separating intermediate lane guides to assure equal widths.
Since all lanes are maintained with equal widths, the prior art devices are effectively limited to relatively small lane width adjustments. The prior art devices would not efficiently handle articles wherein larger ones of the articles have widths about two or more times greater than widths of smaller ones of the articles conveyed. In order to accommodate such a range of article widths, prior art conveyors would have to be twice as wide as necessary to handle only the smaller size ones of the articles.
The prior art devices are also designed for downstream operations using the same number of article single files regardless of article size. Thus, prior art devices would not efficiently service downstream operations in which article width is inversely related to the required number of lanes.
For example, in food or beverage plants, cases of cans (e.g., 12, 24 or 32) are packed either from individual cans, or from six-packs or other prepackaged units of cans (e.g., 8-packs or 12-packs). Although the prepackaged units are articles of greater width than the individual cans, fewer lanes of units are needed to pack a case.
What is desired, therefore, is a laning conveyor which can efficiently and effectively handle articles whose widths vary by a factor of about two or more. A laning conveyor in which the spacing of less than all the lanes may be adjusted for accommodating articles of different widths is also desired.